Made a relatively huge mistake when washing the m3 today. Was out of bmw wheel cleaner (the nasty smelling stuff that turns red) and too lazy to go to a dealer 15-20mi away, went for Mother's wheel foam.

What I normally do is spray a minute or two before the car goes into a car wash.

Holy crap... Wheels have cloudy marks on them that don't come off. This s**t hurt the clearcoat in minutes. Ugh. Lesson learned.

Now it is possible that OEM clearcoat would have survived it. I had the wheels done last year.

Maybe it time to powder coat them black ... I did this to my 911 and it looks really good. I know a lot of people here don't like the look but it is a nice change.

The thread on wheel cleaner is interesting. Maybe I am just lucky, but I've never had any trouble getting brake dust off just using the same Meguiars Gold Class soap I use on the rest of the car.

The regular Gold Class car wash stuff is what I use half the time. When I do wheels with it, it's kind of an involved process that takes some effort and requires filling/emptying/rinsing an extra bucket. The results are nice...it just takes effort to get there.

Sonax? Spray it on. Wait a few minutes. Rinse with hose. Maybe touch up some crevices with a rag, depending on wheels. Done.